Belt-tightening device



Jan. 2, 1945. H. P. THOMAS 2,366,159

BELT TIGH TENING DEVICE Filed April 14, 1943 a INVENTOR. 4 4 2 3g HAYDN P, THOMAS -l enlarged scale.

' Patented Jan. 2, 1945 Haydn P. Thomas; East Moline, 11L. assignor .to iDeere & Company, Moline, 111., a corporation of Illinois ApplicationApriY s, 1943, Serial No. 483,668

10 Claims. (.01. I l-242.10)

The present invention relates to belt tightening devices and. has for its principal object the prof vision. of a quickly releasabl means for securing a belt tightener sheave in several difierent posi tions of adjustment in order to controlthe tension in a power transmitting belt. A further. object of my invention. relates to the provision of a belt tightening device which can be installed in places which are restricted in space and difficult of access.

This inventionyis particularl well adapted, but" not limited to controlling the tension of the main drive. belt, on the cylinder of a combine, in which the belttightener is usually located between the thresher body and the grain tankin a. rather limited amount of space, In this preferred emf bodiment ofmy invention. the main drive belt is a. V-be1t operating over a pair. otgro'oved ulleys;

at least one of the latter being'of adjustable diflameter to obtain an adjustmentv of the speed of the threshing cylinders Whenever an adjustment made of the diameter of one of the pulleys it has heretofore been necessary for the operator to Walk around to. the rear of the grain tank in order to release the tension on the belt tightening device sufllciently to permit an adjustment offthe pulley diameter,after which it was again necessary to adjust the belt tighter to tighten the belt from a position behind the grain tank. It is a more specific object of my invention therefore, to provide a. novel and simple belt tightener, which can be controlled from a position adjacent the adjustabIe V-belt'pulley, thereby eliminating any necessity for the operator. to walk aroun'd'to the rear of the grain tank in order toadiust the Figure 1 is a side elevational view of rthe pre- {erred embodiment of my invention, showing the parts in their normal operating position;

Figure 2 is a side elevational viewofthe belt tightening device, drawn to an enlarged scale and showing the parts in the position in which-the belt tightenereanbeloosened; 1 s l i Figure 3 is a plan view of the belt tightenin device; and l Figure: 4 is. a. sectional elevational view taken along a line 4-4 in Eigure 3 and drawn to an Referring now to thedrawing, referehcenumeral Sindicates a drive belt, inthis case a V- belt of any conventionaldesign. The belt 5 1s trained over a drive pulley 6 mountedon a drive shaft 1', and over a driven pulley a mounted on the cylinder-shaft 9 of the combine. The pulleys 6 and 8 are preferably of the usual V-grooved type adapted to receive the tapered sides of the V-belt 5. Thedrl'ven pulley 8 is preferably of the adjustable diameter type which is well-known to those skilled in the art and needs nodetailed explanation here; since the details of the; pulleys and belt have no specific bearing on the operation of the belt tightening device which is the subjectof the present invention; l

The belt tightening device comprises an idler sheave "I of suitable grooved conformation to receive the slack side of. the drive belt-5. The sheave l0 isjournaled on'a stub shaft llgwhich is supported in a U=shaped yoke member I 2. The yoke I 2 is mounted on the free end of an arm l3, whichis pivotally mounted at its opposite end on a bracket M by means of a pivot bolt l5. The bracket I4 is secured rigidly to a relatively stationary frame member-t5." Thustheshearze I0 can be moved from a. relatively loose engagement with the drive belt 5 to a belt tightening position by swinging the yoke and arm H in. acounter clockwise direction about the bolt H, as viewed in Figure 1. l

The sheave I0 is retained in belt tightening position by means of a tensioning device, indicated generally by referencenumeral 2B, which 7 prising a short length'of structural angle member 7 24, disposed in anupwar dly and rearwarclly inclinedposition and supported on a.v bracket 25 by means ofa bolt 26. The bracket 25 is fixed to the main supporting frame 16. 1

r The angle member 24 is disposed with one flange 24a lying in a plane substantially transverse to the bar 2! and. hasa slot Zl provided adjacent the other 'flange, 24b. The slot is adapted to receive the bar 2| in slidable relation,and the lower edge of the bar 2[ is notchedto provide a plurality of teeth 28, which. are inclined in a dire'ction toward the sheave H). In other words, the teeth. 28 are in efl'ect. ratchet teeth, each of which has a front side toward the sheave disposed in a planev substantially perpendicular to the bar and its rear side away from the sheave inclined to the major axis of the bar H. The teeth 28 are adapted to engage the lower edge 21" of the slot 21 to restrain the idler ID in belt tighteningposition and to prevent the arm-I3 from swinging in a clockwise direction as viewed in Figure 1. The bar 2| is urged downwardly to maintain the pushing the idler l rearwardly, which will cause the teeth to ratchet over the engaging edge 21-, since very little resistance to movement in this direction is offered by the inclined edges of the comprises a bracket 48 in the form of a bar secured as by welding to the side of the bar 2|, and

a strap member 41 is connected to the bar by' bolts 48 and provides a slot between the bar 46 and strap 41, through which is slidable the control lever 35.

, It is evident to those skilled in the art that the device described above greatly facilitates the operation ,of adjusting the speed ofthefdriven shaft 9, for the idler l0 can be quickly and easily released from tightening position by pressing down on the lever 35 and pulling it forwardly, after this direction is easily accomplished by merely teeth 28. Thus, the bar 2| will slide through the 1 slot 21 and through the clip 30, but the teeth 28 will secure the bar in any position of adjustment, and prevent it from moving forwardly toward belt loosening.position,: The vbelt c'anbe loosened, however, by raising the rear end of the bar 2| against thepressure of the Spring 29, thus disengaging the teeth 28 from'the lower edge 21' of the slot 21, aftenwhich the bar 2| can be slid forwardly through the upper portion of the slot 21 Heretofore however, it has been necessary for the operator to take hold of therearendof the bar 2| .to lift the teeth out of engagement, and this is notalways easily accessible to the operator from av position in frontof the idler sheave ID, forit is sometimes desirable to place the tightening device in a restricted space, such as between twopieces of equipment, foreXarnple, between the body and grain tank of a combine. According to thjepresent invention, however, this adjustmentis easily made from aposition in front of the idler she'ave lrfl, by meanslof a control lever 35, which is pivotally connected to the rear end of the bar 2| by mean of apivotybolt 36, which passes through alignedapertures in thebar 2| and lever and also through a spacing collar 31. therebetween, Thecontrol lever 35 extends forwardly alongside the notched bar 2|, and is supported in a-strapmember 38, which is secured to the fore andaft' BXtendi'ng flange 24!) of the angle, guide member .24, by means of bolt 39. The'forward end of'the control lever 35.,is provided with a laterally turned ,endAO, serving as a handle." I l Itis now evident that the',r ear end of the bar 2 I can be lifted by depressing the handle 40, cans ing the lever35 to bear upon the'strap member 38 as a fulcrum and raise the rearen d of the bar 2|,rthro'ugh the pivot bolt 36. After the lever 35 has been pushed downwardly sufficient to disengage the teeth 28 from the lower edge 21' of the slot,the lever 35 can be pulled forwardly by means of. the handle 48, thereby sliding the lever 35 along its fulcrum and carryingjwith it the notched ,bar 2|, which slides throughtheslot 21 and through the spring clip member 30. {Whenever the handle Allis releasedthe spring 29 pullsthebar .2 downwardly and engages theteeth witlithe engaging Bd e2.'|

As explained'above the belt can beretightened by merely pushing rearwardly on the idler. sheave lllor on the control handle 40, whereupon the t eth, 28 of the bar 2l slide over the engaging edge 21 ,and h'oldthe bar 2|. in any adjusted position. .f s Another guide 45 provided toward the forward ends of the bar 2| and lever. 35, to secure the latter against lateral Vibratibn. This guide 45 which the necessary adjustment to the pulley 8 can be accomplished, after which the belt is retightened by merely pushing rearwardly on the idler l0 until the belt is tight.

I claim: I 1. In a belt tightener comprising a yoke and a sheave journaled therein, a quickly releasable tensioning means comprising a notched member fastened to said yoke, a support and guide member for said notched member and having a part engageable with the notches on thelatter; spring means retaining said members in engaged' rela tion but yieldable to permit disengagementthereg of, and a pivotally supported control element en gaging said members and swingable toiforce the latter apart to disengage them against the action of said spring. v

2. In a belt tightener comprising a yoke and a sheave journaled therein, a quickly releasable tensioning means comprising a member fastened to said yoke and having inclined ratchet teeth along one side thereof, a support and guide mem; ber for said toothed member, having a'part en gageable with said ratchet teeth providing for relative movement therebetween for shifting said notched member to tighten the belt, but retaining the same in adjused position, spring means re taining said members in engaged relation but pivotally supported control element engagingsaid members and swingable to forc'ejthe latterapart to disengage themv against the action of said sprin 3. In combination, a belt tightener sheave, a yoke journaled thereon, a supporting'farm attached to said yoke at one end of said arm,the other end being pivotally supported. for swinging said sheave between tight and loose positions relative to a belt, and a quickly releasable tensiohing ,means comprising a bar member pivotallylcon nected to said yoke and having inclinedra'tchet teeth along one side thereof, a support and guide member for said toothed member having a part engageable with said ratchet'teeth providing for relative movement therebetween for shifting said notched member to tighten the belt,bu t retaining the same in adjusted position, spring means retaining said members in engaged relation but yieldable topermit disengagement thereof andfa control element connected to one of said members and adapted to act against the other member-{for disengaging said members to permit loosening of the belt.

4. In a belt tightener comprising a yoke and a sheave journaled therein, a quickly releasable tensioning means comprising anotched member fastened to said yoke, a support and guide mem' ber for said notched member, having a part engageable with the notches on the latter" and biased into engaged relation, but yieldable'to perinit disengagement thereof, and a shiftably mounted releasing control handle acting between said members to disengage said notches from said said guide bysliding said lever along said fulpart.

5. In a belt tightener comprising a yoke anda sheave journaled] therein, a quickly releasable tensioning means comprising a notched member fastened to said yoke, a guide member for ,said notched member, having a part engageable with the notches on the latterand biased into engaged relation, butyieldable to permit disengagement thereof, and a release lever pivotedonone of said members and swingable into engagement with theother of said members to disengage said members. i

6. In a belt tightener comprising a yoke and a sheave journaled therein, a, quickly releasable tensioning means comprising a member fastened to said yoke and havinginclined ratchet teeth along one side thereof, a guide member for saidtoothed member, having a part engageable with said ratchet teeth, the latter being s'lidable relative to said part in a belt tightening directionbut held against movement in a loosening direction, means biasing saidmembers into engagement, and a control lever pivoted on one of saidmembers and swingable into engagement with the other of said members to separatesaid teeth from engagement with said part to loosen the belt 7. In a belt tightener comprising a, yoke and a sheave journaled therein, a quickly releasable tensioning means comprising a notched member j fastenedto said yoke, afguide, member for said notched member, having a. part engageable with the notches on the latter and biased into engaged crum. i i

8. The combination set forth in claim 7 including the further provision that said notched memberand control lever comprise a pair of bars pivotally connected together and supported on said guide member, which also serves as said fulcrum. 9. In a belt tightener comprising a yoke and a sheave journaled therein, aquickly releasable tensioning means comprising a notchedbar attached at one end to said yoke and supported in :a guide member having a part adapted to engage the then shifted longitudinally to adjust thetension 1 i on the belt. l 10.111 combination, a belt tightener sheave, a yoke in whichsaid sheave is joumaled, a supporting arm attached to said yoke at one end of said arm, theother end being pivotally supported for swinging said sheave between belt tightening and belt loosening positions, a bar pivotally connected i at one end with said yoke, a guide member carryrelation, but yieldable topermit disengagement 1 thereof, a release lever pivoted on said notched member and extending generally parallel thereto,

and relatively stationary fulcrum means for receiving said release lever to permitsaid notched member to be raised out of engagement with said part, said lever being slidable on said fulcrum whereby said tightener can be shifted relative to,

ing the other end of said bar, the latterbeing provided with ratchet teeth permitting free movement of said sheave to tightening position but retaining said sheave in said tightening position,

spring means yieldably urging said members into engagement, and a release control lever pivoted R to the other end of said bar and slidably supported on said guide member, said lever having a handle adjacent said yokewhereby the lever can be swung to disengage said notched bar from said guide member and then shifted longitudinally to 40 belt loosening position; I v

o HAYDNP. THOMAS. 

